1. Field of the Invention
This invention relates to 2-iodo-1,1,2,3,3-pentahydroperfluoroalkyl borates and their preparation from perfluoroalkyl iodides and triallyl borate in the presence of a free radical initiator. It relates also to the process of preparing perfluoroalkylpropylene iodohydrins by hydrolysis of the borates of this invention.
2. Description of the Prior Art
Japanese Pat. No. 79011284 to Daikin Kogyo discloses the .alpha.,.alpha.'-azobisisobutyronitrile (AIBN) initiated addition of perfluoroalkyl iodides to allyl alcohol, at a molar ratio of R.sub.f I to allyl alcohol of 0.5:1.0 and a molar ratio of AIBN to R.sub.f I of 0.10.
N. O. Brace reported in J. Organic Chemistry 27, 3033 (1962) the addition of 1-iodoperfluoropropane to allyl acetate, initiated by 0.02 mole AIBN per mole of C.sub.3 F.sub.7 I.
This invention provides several advantages over the prior art. Higher conversions are obtained in less reaction time with the process of this invention. Lower levels of the free radical initiators are used in this invention, thus minimizing by-product formation. Because of similarities in boiling points, unreacted iodide is difficult to separate from the borate or iodohydrin products. The borates of this invention and the iodohydrins prepared from them are of high purity, as there is little unreacted material.